This invention relates to materials and process for recording information onto a copy sheet. More specifically, the invention relates to transparent colored ferromagnetic materials for use in magnetic imaging systems.
Various systems are well known for high volume duplicating of copies including mimeograph, spirit duplicating, lithography, and the like. At the same time, there are known reproduction systems generally regarded as more suitable for lower volume rates such as xerography and photography which offer the distinct advantage of an optical input in reproducing a copy of an original.
In accordance with this invention, there is at least partially employed the process of xerography as, for example, disclosed in Carlson, U.S. Pat. No. 2,297,691, issued Oct. 6, 1942, or may include variations thereof for placing a developable image charge pattern on a support as disclosed, for example, in U.S. Pat. Nos. 2,825,814; 2,919,967; and 3,015,304. Likewise a latent magnetic image could be formed and utilized as disclosed in U.S. Pat. No. 2,857,290. As first taught by Carlson, a xerographic plate comprising a layer of photoconductive insulating material on a conductive backing is given a uniform electric charge over its surface and is then exposed to the subject matter to be reproduced, usually by conventional projection techniques. This exposure discharges the plate area in accordance with the radiation intensity that reaches them, and thereby creates an electrostatic latent image on or in the photoconductive layer. Development of the latent image is effected with an electrostatically charged, finely-divided material such as an electroscopic powder that is brought into surface contact with the photoconductive layer and is held thereon electrostatically in a pattern corresponding to the electrostatic latent image. Hereafter, the developed xerographic image may be affixed directly to the surface on which it is developed, or as usually performed, is transferred to a secondary support on which it is affixed by any suitable means.
Now in accordance with the instant invention, there is provided selectively colored magnetic materials for use in color magnetic imaging systems.
It is, therefore, an object of this invention to provide novel materials for copy duplicating.
It is a further object of this invention to provide novel transparent ferromagnetic materials.
It is a further object of this invention to provide the formation of transparent amber to red colored materials which are magnetic.
It is a further object of this invention to provide a fine dispersion of ferrimagnetic material throughout a highly porous silicaceous material.
It is still a further object of this invention to provide a process of producing transparent magnetic particles.
It is still another object of this invention to provide transparent magnetic particles of a desired color.